The Distribution of Soil Carbon and Nitrogen Stocks Among Dominant Geomorphological Terrain Units in Qarlikturvik Valley, Bylot Island, Arctic Canada

Soils of circumpolar regions store large amounts of carbon (C) and are a crucial part of the global C cycle. Yet, little is known about the distribution of soil C stocks among geomorphological terrain units of glacial valleys in the Arctic. Soil C and nitrogen (N) content for the top 100 cm of the d...

Full description

Saved in:
Bibliographic Details
Published in:Journal of geophysical research. Biogeosciences 2022-07, Vol.127 (7), p.n/a
Main Authors: Ola, A., Fortier, D., Coulombe, S., Comte, J., Domine, F.
Format: Article
Language:English
Subjects:
alluvial fan
Alluvial fans
Arctic
Atmospheric models
Carbon
Climate
Climate change
Climate models
Depth
Distribution
Earth Sciences
Environmental Sciences
Gases
Geochemistry
Geomorphology
Global warming
Greenhouse effect
Greenhouse gases
Nitrogen
Permafrost
Plant cover
Polar environments
polygon
Polygons
Sciences of the Universe
Soil
Soil analysis
Soil characteristics
Soils
Stocks
Terrain
tundra
Valleys
Vegetation
Vegetation cover
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Soils of circumpolar regions store large amounts of carbon (C) and are a crucial part of the global C cycle. Yet, little is known about the distribution of soil C stocks among geomorphological terrain units of glacial valleys in the Arctic. Soil C and nitrogen (N) content for the top 100 cm of the dominant vegetated geomorphological terrain units (i.e., alluvial fans, humid polygons, mesic polygons) at Qarlikturvik Valley, Bylot Island, Canada have been analyzed. Soil C content was greatest in humid low‐center ice‐wedge polygons (82 kg m−2), followed by mesic flat‐center ice‐wedge polygons (40 kg m−2), and alluvial fan area (16 kg m−2), due to prevailing geomorphological processes, differences in vegetation and soil characteristics, as well as permafrost processes. Soil N content was greatest in humid polygons (4 kg m−2), followed by mesic polygons (2 kg m−2), and alluvial fan area (1 kg m−2). Vertically, C and N decreased with increasing depth except for a peak in C at depth in humid polygons, a likely result of past changes in vegetation cover. At Qarlikturvik Valley, which has a size of 121.7 km2, alluvial fans store 0.226 Tg organic C and humid and mesic polygons store 1.643 and 0.218 Tg organic C, respectively in the top 100 cm of soil. Findings like these are important to further constrain pan‐Arctic soil C and N stock estimates and thus climate models. Plain Language Summary Permafrost soils of the Arctic store large amounts of carbon (C) and nitrogen (N), which may be emitted to the atmosphere in form of greenhouse gases further enhancing global warming when thawed under warmer conditions. It is therefore important to know how much C and N these soils store. Various approaches have been used for upscaling in the past. Here, soil C and N stocks were estimated for the main vegetated geomorphological terrain units of a valley in the Arctic. Soil C and N levels varied among geomorphological units, due to prevailing geomorphological processes, differences in vegetation and soil characteristics, as well as permafrost processes. Overall, C and N decreased with increasing depth. These data will allow us to better constrain soil C and N stocks of permafrost regions and ultimately climate models. Key Points Geomorphological terrain units differ in soil carbon and nitrogen stocks and should be considered in Arctic soil inventories Humid low‐center ice‐wedge polygons store larger quantities of soil carbon and nitrogen than mesic flat ice‐wedge polygons and all
ISSN:2169-8953
2169-8961
DOI:10.1029/2021JG006750